Process and apparatus for coagulating and drying latex

Abstract

A process for the continuous coagulation and drying of rubber latex includes feeding the latex onto an endless conveyor belt which feeds the latex through a coagulator. A combination of microwave energy and hot air raises the temperature of the latex causing it to coagulate in a coagulation time of less than five minutes. The coagulated rubber from the coagulator is fed into a conveyor belt of a stretch unit which stretches the rubber by increasing its speed of travel. The stretched rubber is then conveyed onto the upper belt of a drying unit. The drying rubber is passed from the upper belt onto an intermediate belt and then on to a lower belt before leaving the drying unit. A combination of microwave energy and hot air in the drying unit is used to dry the rubber to a moisture content of less than 1.5%.

What is claimed is:  
     
       1. A process for continuous coagulation and drying of rubber latex, comprising passing a stream of the latex through a coagulator to form a coagulated rubber stream, wherein a coagulation temperature in the coagulator is in the range from 30° C. to 90° C., introducing the coagulated rubber stream from the coagulator into a dryer downstream of the coagulator, and passing the coagulated rubber stream through the dryer to dry the rubber, in which the latex stream in the coagulator is heated by a combination of microwave energy and hot air. 
     
     
       2. A process as claimed in  claim 1 , wherein the latex stream entering the coagulator has a thickness in the range from 1.0 mm to 15.0 mm. 
     
     
       3. A process as claimed in  claim 1 , wherein the coagulated rubber in the dryer is heated by a combination of microwave energy and hot air. 
     
     
       4. A process as claimed in  claim 1 , wherein the rubber is dried to a moisture content of less than 1.5%. 
     
     
       5. A process as claimed in  claim 1 , wherein the latex stream speeds, rubber temperatures and microwave energy consumption are computer-controlled. 
     
     
       6. A process as claimed in  claim 1 , further including stretching the coagulated rubber stream passing between the coagulator and the dryer. 
     
     
       7. A process as claimed in  claim 6 , wherein the coagulated rubber steam is stretched by increasing its speed of conveyance to the dryer. 
     
     
       8. A process according to  claim 1 , wherein the latex stream entering the coagulator is carried on a conveyer belt.